Centrifugal machines



June 4, 1963 H. F. lRvlNG 3,092,580

CENTRIFUGAI.. MACHINES Original Filed Deo. l5. 1954 2 Sheets-Sheet 1 np:Z INVENTOR mig- ATTORNEYS June 4, 1963 H. F. lRvlNG 3,092,580

CENTRIFUGAL MACHINES Original Filed Dec. 15. 1954 2 Sheets-Sheet 2 fg: 4686 55 63a INVENTOR H ewzifz ATTORNEYS United States Patent O 3,092,580CENIRIFUGAL MACH-ENE@ Henry F. Irving, Saginaw, Mich., assigner toBaiser Perkins Inc., Saginaw, Mich.

@riginal application Dec. 13, M54, Ser. No. 474,940, new Patent No.2,899,1365, dated Ang. 11, 1959. Divided and this appiieation dan. 26,1959, Ser. No. 789,031

3 Claims. (Cl. 21--376) This invention relates to new and usefulimprovements in centrifugal separating machines and more particularly tocontinuously operable machines of this type which are well-suited toseparating a Variety of granular, fibrous, or crystalline solids fromliquid mixtures containing the same.

Continuously operating push-type, single stage centrifuges have longbeen employed. for effecting the separation of liquid and sol-ids andare relatively well known. However, it is an object of the instantinvention to provide a machine of this type which is particularlywelladapted to separating sugar crystals from a slurry or mixturecomprising the crystals and syrup or mother liquor although having ageneral adaptability for other purposes. The present application isdivisional from application Serial No. 474,940, led December 13, 1954,now Patent No. 2,899,065.

A principal object of the invention described herein is to design amachine of this type in which means is provided for mixing therelatively wet strata of caked solid directly adjacent the basket withthe drier solids above it as the cake is discharged so that lumps ormasses of sticky crystals which build up and break off will not form onthe dry housing wall adjacent the basket.

A still further object of the invention is to design a centrifugalmachine of the type described which is durable and rugged inconstruction, which comprises relatively few component parts of a simplenature which are readily accessible for cleaning and inspection, whichmay be easily and simply disassembled for repair and replacement ofparts, and will accordingly be relatively inexpensive to maintain andwhich can be economicmly manufactured and assembled.

With the above and other objects in view, the present invention consistsin the combination and arrangement of parts hereinafter more fullydescribed, illustrated in the accompanying drawings, and pointed out inthe appended claims, it being understood that equivalent changes may bemade in the various elements of the invention, without departing fromthe spirit of the invention or sacrificing any of the advantagesthereof.

In the drawings:

FIGURE 1 is a part sectional, side elevational View of my novelcentrifuge showing the pusher in forward position.

FIGURE 2 is an enlarged, fragmentary, sectional view thereof, the pusherbeing shown in rearward position.

FIGURE 3 illustrates schematically the manner in which the pusher isactuated forwardly by a hydraulic pump and is permitted to return underpressure of the material feeding into the basket.

FIGURE 4 is a sectional View illustrating schematically one of themultiple way valves which is employed in the system.

FIGURE 5 is a sectional View illustrating schematically another valvewhich is employed in the system to control the valve shown in FEGURE 4.

FIGURE 6 is an enlarged, fragmentary view showing the material forcingthe pusher rearwardly.

FIGURE 7 is an enlarged, fragmentary View showing the circumferentiallyspaced lugs which connect the intermixing baffles to the basketthrow-off ring.

Referring now more particularly to the accompanying drawings wherein ihave shown preferred embodiments of my invention and more particularlyto FIGURE l, the machine comprises a base iii with a drive housing 11supporting bearings 12 and 13 in which a tubular drive shaft 14 isjournaled. A dri-'1e sheave 15 mounted on the reduced end 14h: of theshaft 11iis connected by belts 16 to the shaft of a motor 17 which isadapted to drive the shaft at relatively high speeds.

Formed as an integral portion of the shaft 14 is a pressure fluidcylinder 13, the two portions of which may be bolted together as at 19.A piston 2d keyed in the cylinder as at 21 so as to rotate therewith, isprovided in the cylinder 13, and is reciprocated in the cylinder in amanner which will be later described. A pusher control assembly C ofconventional design is provided to control the forward operation of thepiston 2u and the piston rod or shaft 22 is transversely bored as at 23and longitudinally bored as at 24 to admit pressure fluid from theassembly C to the outer face of the piston 2t) so as to drive the latterforwardly to the piston in which it is shown in FIGURE l. Provided inthe shaft 14 and communicating with the passage 23 when the piston is inrearward position is a port 23a leading to the control assembly C.Further, the internal diameter of the shaft 14 is enlarged as at 25 totransmit tluid to the control assembly C through the transverse passage25a when the piston is moved forwardly and to admit fluid to the frontface of the piston when it is returned to original position by repressure of the material feeding into the basket as will later bedescribed. A positive displacement constant delivery pump d4 (FiGU-RE 3)supplies the pusher control assembly in a manner which will later becomeapparent.

The tubular shaft 14 extends from the drive housing 11 into a wethousing 26 which is bolted to the housing 11 and a drum `or basket B iskeyed thereon as -at 27, the basket B comprising a radial end wall orhub 28 with a perforated cage 29 having a screen 3d supported therein. Afrusto-conical pusher Wall 31 is keyed as at 32 to the tapering end ofthe shaft 22 which extends into the wet housing 26 beyond the shaft 1/1,and a nut 33 threaded on the end of fthe shaft 22 maintains the Wall 31in position. The wall 31 has a laterally turned ange 31a which isrecessed as at 31h to receive a scraper ring 34. Additionally, anaccelerating funnel or distributor member 35 having a laterally turnedflange 35a is supported a spaced distance from the portion 31a of thewall 31 on circumferentially spaced, integral lugs or bosses 36 formedon the ange 31a so as to form passages 37 between the anges 31a and 35aleading to the screen 30. The funnel 35, it will be observed, isconcentric with the screen 39 and is substantially co-exten? sivetherewith. The annular `flange portion 35a of the funnel 35 terminates aspaced distance from the basket 30 and serves as a leveling ring.

The outer end wall of the funnel 35 is bored las at 33 to freely admitthe slurry supply pipe 39 and the interior wall thereof is recessed asat 4d to carry a pair of superposed frusto-conical screens 41 and 42,the top screen i1 being a woven screen and the under screen 42) whichsupports the screen 41 being a mesh screen. Connecting with the inneredge of the recess 4@ are anguiar passages 43 which lead through theflange 35a of the funnel and communicate with the passages 44 throughthe flange 31a of the pusher wall 31. When the wall 31 is in rearmostposition as shown in FIGURE 2, it is spaced from the hub 28 of thebasket to form a chamber 45, and liquid proceeding through the passages44 will pass yto the wet housing 26 through the circumferentially spacedports 45a in the basket B immediately adjacent the wall 28 when thepiston 20 is in its rear position as well as when it is in its forwardposition.

The outer end wall of 'the Wet housing 26 terminates short of the basketB and a throw-off ring 46 including an outwardly tapered flange 46aextending into a dry housing 47 is provided on the outer end of thebasket B. Supported outwardly of the flange 46a to rotate with' thebasket B is a frusto-conical baille member 49 which includes a lateralange 49a projecting radially inwardly beyond the screen 30 to channelthesolids discharged down to the passage 50 defined between the rearwardlyand inwardly extending portion of the baffle 49 and the ring 46. Thebaffle portion 49 is secured to the base of the member 46 by widelyspaced lugs 43 which also support a forwardly and outwardly extendingtruste-conical baffle member 51 which directs the flow -of solids fromthe annular passage 50 to the dry housing proper. The baies 49 and 51effect a through intermixture of the relatively wet solid particlesimmediately adjacent the screen and the relatively drier particlesinward thereof in a manner which will be later described. The particleswhich were disposed in the caked mass immediately adjacent the screenmay have a residual liquid content of from 4% to 6% by weight, and thisis what is meant by the term relatively wet as used in the specificationand claims. The liquid content of the solid particles in the cake whichare located radially inward of these particles will be 1% to 2% byweight and these particles will be accordingly termed relatively dry.

The mixture may be Washed in the pre-draining stage of centrifugation bythe laterally directed spray from a hose 52 which enters the stationarysupply pipe 39 through a seal 53 and has a nozzle 52a on the end thereoffor directing the wash liquidto the solids on the sides of the funnel35. The spray from a second wash hose 54 can be directed to the materialon the inner portion of the screen 3i) to remove any remainingimpurities. Partitions 55,56 and 57 separate the wet housing 26 intocompartments 58, 59 and 60 which can be drained olf separately throughthe discharge pipes 61 and, as will be apparent, the so-called green andwash liquids may be segregated in this manner. A conveyor (not shown)may be provided in the lower portion of the dry housing to carry voffthe dried and interrnixed crystals.

The pusher wall 31 is shown in rearward position in FIGURE 2, and itwill be clear that` this wall is moved forwardly to the position inwhich it appears in FIGURE 1 when pressure iiuid reaches the rear faceof the piston through the ports 23a, 23, and 24, and exhausts from `thefront of the piston through the passages and 25a. This pressure iiuid issupplied from a reservoir 62 `(see FIGURE 3) through lines 63 and 63a by'the pump 64 which forces the fluid through a multipleway valve 65 andthence into the colllection chamber 66 in the collector C. The iiuidwhich is forced out of Vthe cylinder 18 when the piston 20 movesforwardly moves through the passages 25 and 25a in-to the collectionchamber 67 in the collector C, thence :through a line 68, back -to thevalve 65, and finally into a line 68a which leads to the reservoir 62.Alternatively, the uid 'could return lthrough the line 96 which willlater be discussed.

The valve 65 (see FIGURE 4) is formed with an in- 'terior cylinder 69 inwhich is a slide 70 having lands 71, 71a, 72, and '73. Passages 74, A75,76, '76a and 77 which communicate with the lines 63, 63a, 68h, 68a and68, respectively, lead into the cylinder as shown, and in the positionin which the valve is depicted the lines 63 and 63a and 68V and 68a, areclearly in communication, and the piston 20 is accordingly movedforwardly. The position of the member 70 is controlled by anothermultiple-way valve 78 which has a slide 79 in the cylinder -80 formedtherein. The one end of the slide 79 which vhas interior lands S1 and 82extends from the valve housing and has spaced-apart flanges 84 thereon.A pin 85 Xed on the shaft 22 `and movable in a slot 85a in the shaft 14has an annular ring 851; disposed between these flanges 84 and clearlyas the piston 20 moves forwardly, will -tend to force the slide 79":tothe right.

Passages 86, 86a, 87, 88 and 89 communicate with the interior of thecylinder 8G, the passages 86 and 86a communicating with a line 90leading to the reservoir, the passage 87 communicating with a line 91leading to a passage 92 in the one end Wall of the valve 65, the passageSS communicating with a line 93 leading to the line 63, and the passageS9 communicating with a line 94 leading to a passage 95 in the oppositeend wall of the valve 65. During the forward motion ofthe piston 20, thelines 93 and 94 are in communication to keep the valve 70 in theposition in which it is shown. By the time the piston 2.0 has reachedthe front of the cylinder and is beginning to be pushed rearwardly (seeFIGURE 6), the slide 79 has been moved to the right to open up thepassage 87 and line 91 to the passage 88 and line 93 and to permit theline 94 to exhaust to the passage 86 which leads through the line 90 tothe reservoir 62. Thus, pressure fluid is forced through the line 91 tomove the slide 70 to the right and open up the passage 77 and line 68above the valve 65 to the passage 74 and line 63 below the valve.Further, the line 63a will now exhaust to the line 6811 as the piston 20moves rearwardly. Since the line 96 leading to the reservoir 62 isalways open to the line 68, the oil forced through the line 68 Will takethe path of least resistance (the line 96) back to the reservoir 62 andwill not force the piston 29 rearwardly. As the slowly building cake(see FIGURE 6) moves the piston 20 rearwardly, however, oil from theline 68 under virtually no pressure will lill the space in front of thepiston 20 and this is very important since the system must be maintainedin centrifugal balance. The piston 20 will accordingly have a very rapidforward stroke and a relatively slow return stroke controlled by theamount of solid particles being deposited at S' (see FIG. 6). If itappears that the rate of feed is not suicient to build the cake up tothe leveling ring 35a, a conventional relief valve 97 which interposesresistance in the line 68a leading to the reservoir 62 can be cut in toslow the return rate of travel of the piston 20. A system such asdescribed wherein the return travel of the piston 20 depends on the rateat which slurry is fed into the system through the pipe 39 and the rateat which the cake builds is superior in a great many respects toconventional machines. Obviously, there Will not be a continuous workingof the crystals of the continuously building cake which will mean lesscrystal breakdown and less passage of crystals through the screen 30.Further, the rates of feed are often very different and the machine canoperate very eiciently at both low and high rates of feed. In the formercase, the cake will be permitted time to build up to the leveling ring35a so that it will have a maximum retention time on the screen 30. Asthe piston 20 moves rearwardly, the ring 85b will, of course, return theslide 79 to the left yback to the position in which it is shown inFIGURE S and the slide 70 will accordingly be returned to the left asshown. The stroke of the continuously reciprocating wall 31 is such asto discharge only the front portion of the caked solids S which arevirtually free of liquids lto the dry housing 47.

In operation, the sugar slurry or massecuite reaches the interior of thebasket through the stationary pipe 39 and funnel 35 which graduallyaccelerates the mixture prior to discharging it through the passages 37to the screen 3l). The greater proportion of mother liquor is drainedoff to the wet housing 26 through the screens 41 and 42 prior to thetime the mixture reaches the screen 3d and a portion of the washingoperation to remove impurities not carried olf with the mother liquorcan also -be carried out during this pre-draining operation. Liquidpre-drained through the screen 41 travels rearwardly through the meshesof the screen 42 which is within the recess 40 and thence proceedsthrough the passages 43 and 44 to the chamber 45 rearwardly of thepusher wall 31. Ports 45a as previously noted, drain the space 45 to thechamber 58 in the wet housing 26. The wash hose 52 delivers a prescribedspray of water to the mixture on the screen 41 which is insufficient toilood the retained solids such that dilliculty will be encountered inpushing them when they reach the screen. When the solids reach thelatter screen 3i), there is, of course, a relocation of the solidparticles as they pass from the screen 41 and the hose 54 thencecompletes the washing operation.

When the solids are discharged from the outer end of the screen 30 bythe pusher wall 31, the relatively drier particles which were located inthe cake substantially inward of the screen tend to be farmed outwardly,while particles immediately adjacent the screen which are relatively wetwill not necesssarily be perceptibly thrown axially outward of thescreen and in conventional machines would leave the flange 46a of thering 46 in substantially a radial path. These relatively wet and stickycrystals tend to collect and in many instances will adhere and build upon the partitioning wall separating the Wet and dry housings beforebreaking off in relatively large pieces. Since this disposition isunsightly and :the collections of sticky crystals are undesirable in thefinished product, I have found it practical to intermix the relativelywet and relatively drier particles. The portion 49ay of the baille 49catches and dellects the relatively dry particles inwardly to thechannel 50 so that they pass through `and become thoroughly intermixedwith the wetter particles. The resulting intermixture will not collecton the partitioning wall referred to and will provide a uniform product.

It is to be understood that the foregoing drawing .and descriptionthereof is in all cases to be taken as merely illustrative of theinvention rather than as limiting the scope thereof and for adetermination of the scope of the invention attention is directed to theappended claims.

It is further to be emphasized that various equivalent changes may bemade in the various elements which comprise the invention Withoutdeparting from the spirit of the invention or the scope of the claims.

I claim:

1. In a centrifugal machine; a wet housing; perforated separating drummeans therein including a iirst end and a terminal end; means feeding amixture, comprising liquid components which will pass through said drummeans and `solid components which will be retained on the interiorperipheral surface, to said first end of said drum means; a dry housingadjacent the terminal end of said drum means; means for discharging thesolid components retained on said drum means from the terminal end ofsaid drum Imeans to said dry housing; and deflector means mounted onsaid terminal end of -said drum means including a first baille spacedgenerally axially outward from the drum means having a section generallyradially spaced outwardly from the terminal end of the ydrum means toreceive solid components discharged generally radially from said drummeans and inclined inwardly relative to the drum means, channeling thesolids discharged in an axially inward direction to intermix therelatively wet solid components immediately adjacent the inner surfaceof said :drum means with the drier solid components radially inwardthereof; `a second baille, including a section disposed to receive solidcomponents from the inwardly inclined section and located radiallyoutwardly of said inwar-dly inclined section, inclined outwardlyrelative to the terminal end of said drum means to reverse the path oftravel of the components and return them axially outwardly to said dryhousing; and means for rotating said drum means.

2. The combination defined in claim l in which said bales are generallyfrusto-conical in shape.

3. The combination defined in claim l in which circumferentially spaced,radially disposed lugs mounted by said drum means support said bales inposition on the terminal end lof said drum means.

References Cited in the ile of this patent UNITED STATES PATENTS2,052,667 Schmelzer Sept. 1, 1936 2,462,098 Hertrich Feb. 22, 19492,685,370 Ruegg Aug. 3, 1954 2,686,595 Cox Aug. 17, 1954 2,732,073 RueggJan. 24, 1956

1. IN A CENTRIFUGAL MACHINE; A WET HOUSING; PERFORATED SEPARATING DRUM MEANS THEREIN INCLUDING A FIRST END AND A TERMINAL END; MEANS FEEDING A MIXTURE, COMPRISING LIQUID COMPONENTS WHICH WILL PASS THROUGH SAID DRUM MEANS AND SOLID COMPONENTS WHICH WILL BE RETAINED ON THE INTERIOR PERIPHERAL SURFACE, TO SAID FIRST END OF SAID DRUM MEANS; A DRY HOUSING ADJACENT THE TERMINAL END OF SAID DRUM MEANS; MEANS FOR DISCHARGING THE SOLID COMPONENTS RETAINED ON SAID DRUM MEANS FROM THE TERMINAL END OF SAID DRUM MEANS TO SAID DRY HOUSING; AND DEFLECTOR MEANS MOUNTED ON SAID TERMINAL END OF SAID DRUM MEANS INCLUDING A FIRST BAFFLE SPACED GENERALLY AXIALLY OUTWARD FROM THE DRUM MEANS HAVING A SECTION GENERALLY RADIALLY SPACED OUTWARDLY FROM THE TERMINAL END OF THE DRUM MEANS TO RECEIVE SOLID COMPONENTS DISCHARGED GENERALLY RADIALLY FROM SAID DRUM MEANS AND INCLINED INWARDLY RELATIVE TO THE DRUM MEANS, CHANNELING THE SOLIDS DISCHARGED IN AN AXIALLY INWARD DIRECTION TO INTERMIX THE RELATIVELY WET SOLID COMPONENTS IMMEDIATELY ADJACENT THE INNER SURFACE OF SAID DRUM MEANS WITH THE DRIER SOLID COMPONENTS RADIALLY INWARD THEREOF; A SECOND BAFFLE, INCLUDING A SECTION DISPOSED TO RECEIVE SOLID COMPONENTS FROM THE INWARDLY INCLINED SECTION AND LOCATED RADIALLY OUTWARDLY OF SAID INWARDLY INCLINED SECTION, INCLINED OUTWARDLY RELATIVE TO THE TERMINAL END OF SAID DRUM MEANS TO REVERSE THE PATH OF TRAVEL OF THE COMPONENTS AND RETURN THEM AXIALLY OUTWARDLY TO SAID DRY HOUSING; AND MEANS FOR ROTATING SAID DRUM MEANS. 